// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_AURA_CLIENT_EVENT_CLIENT_H_
#define UI_AURA_CLIENT_EVENT_CLIENT_H_

#include "ui/aura/aura_export.h"

namespace ui {
class EventTarget;
}

namespace aura {
class Window;
namespace client {

    // An interface implemented by an object that alters event processing.
    class AURA_EXPORT EventClient {
    public:
        // Returns true if events can be processed by |window| or any of its children.
        virtual bool CanProcessEventsWithinSubtree(const Window* window) const = 0;

        // Returns the top level EventTarget for the current environment.
        virtual ui::EventTarget* GetToplevelEventTarget() = 0;

    protected:
        virtual ~EventClient() { }
    };

    // Sets/Gets the event client on the root Window.
    AURA_EXPORT void SetEventClient(Window* root_window, EventClient* client);
    AURA_EXPORT EventClient* GetEventClient(const Window* root_window);

} // namespace clients
} // namespace aura

#endif // UI_AURA_CLIENT_EVENT_CLIENT_H_
